البحث — المستودع الرقمي العراقي

المستخلص: Silica nano particles were prepared from Iraqi rice husk (al - Najaf province) by precipitation method. Rice husk (RH) was treated with two different concentrations of inorganic acid (i.e. 1 & 3 N HCl) then burning at 700 °C under two heating rates. Chemical composition of rice husk ash (RHA) determined by X - Ray fluorescence (XRF) was contained about 89.5 wt% and 95.2 wt% SiO2 by treatment with 1N HCl at 10 and 5 °C/min heating rates for 3 hrs, respectively. While, XRF analysis was given 97.5 wt% SiO2content in RHA by treatment with 3 N HCl at 5 °C/min heating rates for 2 hrs. 3N HCl and heating rate at 5°C/min seems to be the best method to reduce the metallic ingredients and to obtain highly purified nanosilica powder at a purity of 98.9 wt%.The prepared nanosilica was also characterized by X - ray diffraction (XRD), BET surface, Fourier transform infrared spectroscopy (FTIR) and Atomic Force Microscope (AFM), in order to investigate its properties.X - ray results revealed a strong single beak of 2? at about 22° with an amorphous phase. Surface area was measured for nano silica to be 298 m2/g. The average diameter of prepared nanosilica is 89.58 nm as obtained by AFM analysis. Rice husk is seen to be a frugal waste material, high silica content, and it will be able to apply as a natural source of silica for preparation the zeolite - Y catalysts rather than burnt or dumped it as waste, causing environmental and health problems. On the other hand, the commercial source of silica (i.e. Ludox As - 40) is industrially used with other materials for synthesizing the zeolite type - Y catalyst and economically it has an expensive cost. Hence, it is essential to find out another pathway for silica source.This work deals with the replacing of costly commercial precursors of silica by a cheap natural nano - source silica from Iraqi RH. As such this study focuses on the optimization of percentages of natural and/or commercial silica applied within either seed gel or feed stock gel in the zeolite - Y synthesis process in order to investigate the effect of the nature of the silica used on both the structural properties of produced of Y - catalyst as well as on the catalytic performance of these catalysts in hydrocarbon cracking reactions forimproving the production catalytic activity and selectivity. Commercial zeolite - Y catalyst was laboratory prepared by means of commercial silica source and named as “A” sample, whereas other four samples of zeolite catalysts were successfully synthesized with a desired zeolite - Y phase and so - called “B, C, D and E” using different percentages of natural silica source. All the achieved samples are investigated by characterization techniques (i.e. XRD, BET - surface area, Pore volume, FTIR SEM, AAS, and EDX). The synthesized HY - catalyst samples were catalytically tested in the cracking of Hexane (C6H14) through an experimental cracking rig, and the reaction products were analyzed by GC. The performance of Iraqi RH zeolite type - Y catalysts was compared with the commercial lab HY - catalyst. Catalyst B prepares from only natural nanosilicasource and in comparison with other synthesized Y - catalysts; it gives the best catalytic behavior with 98 - 95 mol% conversion together with the selectivity domination of isomer and normal paraffin within the reaction products during more than 2 hrs at 450 °C. This result confirms that the use of natural silica source can be enhanced the catalytic properties of zeolite type - Y catalyst.

ازالة الكبريت ودراسة الحركية لوقود الديزل بعملية الامتزاز ذو الوجبة باستخدام الكاربون المنشط Desulfurization And Kinetic Study of Diesel Fuel By Batch Adsorption On Activated Carbon

اسم المؤلف: سمر خالد الجنابي

اسم المشرف: نيران خليل ابراهيم

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: تكرير النفط وتقنيات الغاز

الدرجة: ماجستير

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية - فرع الهندسة الكيمياوية وتكرير النفط

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: منتجات التقطير في المصافي , وخاصة قطفة زيت الغاز تحتوي على كميات كبيرة من مركبات الالكيل - بنزوثيوفين والتي هي الاكثر تمردا لازالة الكبريت عن طريق السلفرة الهيدروجينية التقليدية. وتستمر لوائح الوقود في جميع انحاء العالم في التشديد استجابة للحاجة الملحة | Refinery distillates, especially gas oil fractions contain considerable amounts of alkylated benzo - thiophene which are the most recalcitrant to desulfurization via conventional hydrodesulfurization. Fuel regulations continue to tighten worldwide in response to the need to cleaner air and refiners meet these regulations at a very significant cost. The need to cut the operational and capital costs has necessitated a renewed look to the non - hydrogen, low temperature and pressure processes for producing ultra low sulfur fuels.Non - conventional approaches for ultra low - sulfur fuels belong either to oxidative or a selective adsorption routes. The present research focuses on a batch adsorption desulfurization process for diesel fuel containing 580ppm sulfur, based on physical adsorption of refractory sulfur compounds on activated carbon (AC). The effects of time (0 - 3.5 hr), temperature (30 - 70 °C), diesel to AC ratio (2 - 10 ml/gm), AC particle size (0.2 - 1.44 mm), mixing velocity(100 - 1000 rpm), and initial sulfur concentration (280 - 580ppm) in commercial diesel fuel on the desulfurization efficiency were studied. The residual sulfur concentration in diesel fuel was decreased from 580 to 247 ppm, corresponding to a desulfurization efficiency of 57 %, at best conditions of 2.5 hr contact time, 50 ?, 2ml diesel/gm AC, 0.8 mm AC particle size, and 1000rpm mixing rate. The sulfur adsorption dependency on contact time and initial sulfur concentration in commercial diesel fuel (280 - 580ppm) were studied. Different kinetic models : Pseudo - first order (PFO), pseudo - second order (PSO) and intraparticle diffusion models were applied to fit the experimental data. The results of the kinetic analysis showed that the pseudo - first order model underestimates the equilibrium sorption capacity by about 33%. However the pseudo - second order model has succeeded in predicting the equilibrium sorption capacity with correlation coefficient, R2 = 0.995. The experimental adsorption isotherms were correlated by Langmuir and Freundlich models. The results indicated that Freundlich isotherm exhibits the best fits for the adsorptive desulfurization of diesel fuel with correlation coefficient (R2) of 0.989 as compared with the Langmuir model ( ). The adsorption intensity as estimated from the Freundlich isotherm is larger than one which is indicative of physical adsorption.

عمليات التحميض للطبقات المنتجة للنفط الخام في ابار الانتاج البترولية Acidification of Crude Petroleum Bearing Strata In Production Wells

اسم المؤلف: سيف عبد الحق عبد الستار

اسم المشرف: نجاة جمعة صالح

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: تكرير النفط وتقنيات الغاز

الدرجة: دبلوم عالي

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية - فرع الهندسة الكيمياوية وتكرير النفط

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

اختيار الافضل للمفاعل النازل لوحدة التكسير بالعامل المساعد Optimization Technique of Fcc Downer Reactor

اسم المؤلف: علي محسن غضبان

اسم المشرف: Safa A. Al Naimi

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: تكرير النفط وتقنيات الغاز

الدرجة: دبلوم عالي

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية - فرع الهندسة الكيمياوية وتكرير النفط

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: يشتمل البحث على عمل نموذج رياضي لمفاعل النازلdowner) ) في وحدة التكسير المحفز بالعامل المساعد وان التفاعل يشمل اربع مكونات هي التغذية Gas oil)) والغازات الخفيفة (Light gases) والكازولين (Gasoline) والفحم (Coke) اوما يسمى ب Four lumps model لوصف حركة تفاعل | In this work, mathematical model for downer reactor have been developed, in which a four - lump model is used to characterize the feed and the products, where gas oil cracks to give lighter fractions and coke. The integrated reactor steady state model makes gross assumption about the hydrodynamics, using 4th. order Runga Kutta method. Polymath version 5.1 and Aspen version 7.3 programs are used to solve the simulation model. This model can predict the mixing temperature and pressure profiles at mixer (MxR) chamber; also shows the physical performance and productivity all over the downer height. An interactive excel worksheet is constructed and used as a powerful tool for solving the model equations and studying the effect of any change in operating variables on the unit performance. Also observed the simulated results by using two programs (Polymath and Aspen) and the difference between them especially in temperature , pressure and product yield profile plotted along the reactor length and shows that the results from Aspen are better than Polymath because the first is more advanced and accurate. The operation of downer reactor for catalytic cracking is associated with several important objectives such as feed rate and height, diameter of reactor and amount of catalyst rate as well as the production requirements, all of which need to be optimized simultaneously. In this study, a validated mathematical model was used to perform the single - objective optimization of the FCC system at the design stage. In the optimization study, four operating parameters were used as decision variables. These variables were chosen based onsystematic sensitivity analysis of the system which showed complex interplay of the decision variables over the system performance indicators. Elitist Polymath version 5.1 enhanced with Excel flow sheet 2007 were used to solve a number of objective function optimization problems. The objective functions used are maximization of the gasoline yield, and minimization of the catalyst flow rate. The optimal results obtained here provide physical insights that can help in the design stage of the downer reactor.